Dolphins are mammals found in the sea and are part of the toothed whale family. They are grey with backs that are darker than the rest of their bodies.
Dolphins travel in small groups of about 10 to 50 and congregate in schools of greater numbers. The schools are very social and play together. They use echolocation to hunt together to trap their prey. Dolphins are one of the fastest swimming marine mammals and use their speed to help them hunt. Dolphins usually produce one calf, and twins are rare. Females are pregnant from 9 to 17 months, depending on the species of dolphin.